Xanthan gum is a synthetic, water soluble bipolymer derived from the fermentation of carbohydrates by several bacterial species of the genus Xanthomonas and is useful as a thickening and suspension agent in numerous applications. It is tolerant in both strongly acidic and basic conditions and is also heat stable, thereby being useful in many chemical, pharmaceutical and, in particular food applications such as dairy products, beverages and high protein foods.
Xanthan gum displays poor wettability properties however and is very difficult to disperse in water and/or hydrate. A high degree of shear is usually necessary to wet each gum particle in order to disperse it into solution. It is preferably produced as a dry particle for ease in storage prior to end use application and therefore it would be advantageous to develop a substantially dry, dust-free xanthan gum composition that is readily hydratable when ready for use.
A xanthan gum composition with a fast hydration rate would be advantageous in that it can be mixed far more readily into the final food or pharmaceutical product. Xanthan gum as is presently available must be agglomerated in order to increase the rate of hydration. This method of processing is expensive and necessitates high capital expenditures. A fast hydrating xanthan gum composition such as that of the present invention will lower the costs of manufacture by avoiding these costly agglomeration procedures. Moreover, a dust-free product is advantageous from a health standpoint by reducing air borne particles which may be inhaled by workers in the industry as well as lessening the risk of explosion during storage and the prevention of loss of product during storage and transport. A dust-free product will also lessen the number of accidents caused by slippery conditions resulting from spillage of the product.
Historically, when a fast hydrating dust-free powder is desired, the process that is used to achieve these benefits is agglomeration. However, this process is expensive and therefore increases the cost of the final product. U.S. Pat. No. 4,041,234 to Maske discloses dispersible glyoxal-xanthan gum complexes in which glyoxal is added to the xanthan gum fermentation broth in order to improve its dispersibility. However, high amounts of glyoxal are required to adequately disperse the fermentation product when added to an aqueous solution. This is not only a costly procedure but the glyoxal affects the taste of the final products.
U.S. Pat. No. 4,299,825 to Lee discloses concentrated xanthan gum solutions of high viscosity using numerous ultrafiltration steps. However, these comprise only from 8% to 15% xanthan gum and as such exists in solution and is not a dust-free hydratable particle. U.S. Pat. No. 4,670,550 to Bleeker et. al. disclose bipolymer emulsions similar to xanthan gum compositions using high shear techniques, while U.S. Pat. No. 4,254,257 to Schroeck discloses the precipitation of amine salts of xanthan gum from the fermentation broth. Finally, U.S. Pat. No. 4,269,974 to Wintersdorff discloses a smooth flowing xanthan composition wherein the gum is homogenized with vegetable oil and water. However, all of these references recognize the need to shear the gum in order to hydrate it.
U.S. Pat. No. 4,218,262 to Warren teaches a non-clumping, delayed action viscosity increasing agent comprised of xanthan gum that is encapsulated with a coating comprised of a fat selected from the group consisting of fatty acids, mono- and diglycerides of fatty acids and a surfactant selected from the group comprising the alkali metal salts of fatty acids, sorbitan fatty acid esters, linear alcohol ethoxylates, sucrose fatty acid esters and mixtures thereof. The surfactant serves to increase the solubility of the coating and promote wetting of the fatty acid onto the particle. The coating itself has a hydrophilic/lipophilic value of 3.0-10.0.
U.S. Pat. No. 4,654,086 to Baird et. al. teaches and claims a dry xanthan gum composition that is allegedly dispersible and hydratable comprising xanthan gum blended with a surfactant such as acetylated monoglycerides, glycerol esters, sorbitan esters and the like. Optionally, sugar is added but the surfactant must be incorporated in amount of at least 5.0% and may be used in amount of up to 20%. The problem that arises however, particularly in food related applications, is that the surfactant possesses an undesirable taste which is discernable at these levels and makes the xanthan gum inappropriate for use in most food products. Below 5%, however Baird et. al. '086 recognizes that problems regarding hydration and dispersibility arise again.
It is an object of the present invention to provide a substantially dust-free stable xanthan gum hydrocolloid powder that is fully hydratable and useful as a thickener and suspension agent. It is a further object of the present invention to provide a substantially dust-free, fully hydratable xanthan gum composition comprising xanthan gum and very low amounts of a food grade surfactant so as to be undetectable in food applications. It is a further object of the present invention to produce a substantially stable, dust-free xanthan gum composition that is fully hydratable and is an effective thickening and suspension agent in food and drug applications.